Burglar-alarm window guard



Nov. 7, 1939.

H. JACKSON BURGLAR-ALARM WINDOW GUARD Filed Nov. 29, 1937 3 Sheets-Sheet1 a' myfwm@ ATTORNEYS NOV. 7, 1939. H, JACKSON l 2,179,042

BURGLAR-ALARM WINDOW GUARD Filed Nov. 29, 1937 3 Sheets-Sheet 2 m vlNvENToR i ATTORNEYS Nov. 7, 1939- H. JACKSON BURGLAR-ALARM WINDOW GUARDC5 Sheets-Sheet 5 Filed NOV. 29, 1957 ffl!! l Patented Nov. 7, 1939UNITED STATES PATENT oFFicE 3 Claims.

This invention relates to burglar alarm window guards of that generaltype adapted to protect window, door and other openings.

An object of the invention is to provide a lazy tong closure havingnovel joints for effectively mounting the alarm trip cable within theinterior of certain hollow bars of the lazy tong.

A further object is to provide novel switches adapted to be tripped whena surreptitious attempt is made to sever the bars of the lazy tong.

A further object is to provide a lazy tong burglar alarm guard whichwill be formed of a few strong simple and durable parts, which will beinexpensive to manufacture and which will not easily get out of order.

With the above and other objects in view the invention consists ofcertain novel details of construction and combinations of partshereinafter fully described and claimed, it being understood thatvarious modications may be resorted to within the scope of the appendedclaims without departing from the spirit or sacricing any oftheadvantages of the invention.

In the accompanying drawings forming part of this specification,

Figure 1 isa front elevation with parts in section, of a lazy tongburglar alarm guard constructed in accordance with the invention, inextended position.

Figure 2 is a fragmentary front elevation showing one-half rof the lazytong structure, shown in Figure l, in collapsed or retracted position.

f Figure 3 is a detail enlarged sectional View taken on the line 3-3 ofFigure 2 showing one of the joints and the trip cable and pulley.

Figure 4 is a longitudinal sectional view taken on the line 4-4 ofFigure 3.

Figure 5 is an enlarged cross sectional View taken on the line 5-5 ofFigure 2 showing alternate flat and hollow bars forming the lazy tong.

Figure 6 is an enlarged cross sectional view taken on the line 6 6 ofFigure 2 showing a pivotal connection between a hollow bar and a at bar.

Figure 7 is an enlarged longitudinal sectional View taken on the line I'l of Figure 1 and showing the switch and burglar trip cable carried byone of the joints at a bottom mounting hinge of the lazy tong.

Figure 8 is a detail longitudinal sectional View taken on the line 8 8of Figure '7.

Figure 9 is an enlarged detail sectional View taken on the line 9-9 ofFigure 1 and showing the yieldable catch for holding the lazy tong eX-tended.

Figure 10 is an enlarged detail sectional View taken on the line IU-I ofFigure 1 showing the means for securing one end of the trip cable.

Figure 11 is a longitudinal sectional View taken on the line II--ll ofFigure 10.

(Cl. 20D-52) Figure 12 is an enlarged longitudinal sectional i Viewtaken on the line l2-I2 of Figure 1 showing one of the hinges of thelazy tong.

Figure 13 is an enlarged detail sectional View taken on the line lS-ISof Figure l and showing the top hinge to which a padlock may be secured.

Figure 14 is a longitudinal sectional View taken on the line lt-ili ofFigure 13.

Figure 15 is an enlarged longitudinal sectional view taken on the lineIE5- I5 of Figure l and showing the vertical end bar at the free end or"one section of the lazy tong.

In all forms of the invention the alarm circuit may be closed bytampering with the lazy tong such as for instance when rattling the twosecn tions. The current is not being used until such tampering closesthe alarm circuit, or until surreptitious severing of a concealed switchtrap cable is accomplished. Furthermore, the lazy tong may be formedwith alternate bars respectively tubular and lat so that the tubularbars which carry the trip cable are in parallel planes and must beconnected together by a novel type of joint.

Referring now to the drawings in which like characters of referencedesignate similar parts in the various views, I designates a closure tobe protected, ior example a window. In carrying out the invention anovel lazy tong is utilized as a guard, the same comprising two sectionsdesig nated in general by the numeral Il. Each section is secLued at oneend to a respective anchor bar l2. Each anchor bar is hinged to arespective base plate i3 which is secured to the side of the sash byscrews i4, as shown in Figure 12, or other connectors. The free end ofeach section terminates in a respective vertically dis posed bar i5which is provided with a grip it for extending and collapsing thesection.

In the embodiment of the invention shown in Figure 1 each section of thelazy tong is formed of alternate tubular and flat bars il and 1Grespectively, the tubular bars being disposed in parallel planes, asbest shown in Figure 5. As also shown in Figure 5 each flat bar ispivotally connected at the center to the center of the tubular bar whichcrosses it, by means of a pivot bolt l-l which is swivelly mounted onthe ilat bar and is provided with a fork 2B which embraces the tribu--lar bar.

As best shown in Figures 3 and 4, the tubular bars form hosuings for aswitch trip cable 2l. The cable is trained over sheaves 22. Each sheaveis mounted on a shaft 23, which is journaled in a channeled ring 24 thatconnects the flattened ends 25 and 2B of two caps 21 and 28 carried bythe meeting outer ends of each pair of tubular bars. The ring may be Xedto the flattened end 26 by a pin 28 and the flattened end 25 may swivelin the ring to form a pivot. A spacing Washer 29 may be interposedbetween the flattened ends 25 and 26. Removable closures 30 and 3l closeopenings in the sides of the flattened ends 25 and 2B, said openingspermitting assembly of the parts.

As best shown in Figure 6 the meeting outer ends of the hat bars of thelazy tong are pivotally connected together by a pivot pin 32 passedthrough the bars. A spacing washer 33 is disposed on the pivot pinbetween the bars.

As best shown in Figures 1, l0 and ll the trip cable ZI is terminallyanchored to a plug 34 disposed in the lower end of the iinal tubular barof the series. The end of this bar is provided with a hinge eye 35 whichis received between hinge eyes 35 projecting from the bar I5 at the freeend of the lazy tong section. A pivot pin 31 is passed through thealigned hinge eyes.

As best shown in Figures 1, 'l and 8 the opposite end of the trip cableis secured to a stem 38 which is slidably mounted in disc guides 39disposed in the end of the tubular bar I1 which begins the series oftubular bars of the lazy tong. A helical spring 4B is sleeved on thestem and bears against one of the guides and against a collar 4I on thestern` to hold the cable taut. The free end of the stem is formed ofinsulating material 2 which carries a conical switch contact 43.

When the cable 2| is severed the spring 40 expands and moves. the switchcontact 43 to circuit closing position between diverging fingers 44 of astationary switch contact 45, best shown in Figure 8. The stationarycontact is in the form oi a ring which is seated upon a pivot pin 46which is passed through openings in a hinge eye 4l which closes the endof the tubular bar and which is received between hinge eyes 48 carriedby the anchor bar I2, as best shown in Figure 1.

The stationary contact is insulated from the pivot pin and hinge eyerespectively by an insulating bushing 49 and a U-shaped bushing 50.Alarm circuit wires 5I and 52, best shown in Figure 8, are connectedrespectively to the movable switch contact 43 and stationary switchcontact 45. v

As best shown in Figures l, 12, 13 and 14, each section ci the lazy tongis hinged on its respective anchor plate I3 so as to be swung out of theway when not in use, as is customary. For this purpose the anchor plateI3 is provided at spaced points with ears 53 having upstanding hingepintles 54 to receive hinge eyes 55 carried by the bar l2 which supportsthe lazy tong section.

As best shown in Figures 1, 10 and 14 the uppermost hinge eye 55 isprovided with an integral cap 55 in which the uppermost pintle isreceived. Aligned openings 5l and 58 are formed in the cap and pintlerespectively to receive a padlock 55, shown in Figures l and 2 forlocking the lazy tong section in either extended or collapsed position.

The upper end of the initial flat bar is provided with a slot 5B, bestshown in Figure 14 to permit the bar sliding on the pivot pin SI whichsecures the bar at the upper end to ears 62 that project from the platel2. This slot permits folding or the lazy tong section to collapsedposition without binding of the parts.

The vertical bars I5 at the free ends of the lazy tong sections areprovided with orificed ears 63, best shown in Figure 1, to receive apadlock 64 for locking the sections in extended operative position. Saidbars I5 are also provided with spring pressed latches 65 which arereceived in a keeper 66 imbedded in the sash Ill to yieldably hold thesections in extended position. In addition each section is provided witha gravity operated latch 6l slidably mounted on pins 68 carried by thefinal folding ilat bar I8 of the section. The latch is receivable in akeeper 69 countersunk in the bottom of the sash. The latches 65 and 5lhold the sections steady against rattling.

What is claimed is:

1. A burglar alarm comprising a lazy tong closure, said lazy tongincluding crossed bars pivotally connected at their crossing andpivotally connected at their ends, certain of the bars bcing tubular andarranged in such sequence as to form` a continuous passageway, pulleysdisposed at the pivoted ends of the bars forming the passageway, a cabletrained over said pulleys and secured at one end to the initial tubularbar iorm ing the passageway, a switch contact connected to the oppositeend of the cable in the i'lnal bar forming said passageway, and a springconnected to the cable at said contact for maintaining the cable tautand for moving the contact to circuit closing position upon rupture ofthe cable.

2. A burglar alarm comprising a lazy tong closure, said lazy tongincluding crossed bars pivotally connected at their crossing andpivotally connected at their ends, certain of the bars be ing tubularand certain of the bars being hat, the tubular bars alternating with theflat bars, the tubular bars being in parallel rows, hollow pivotalconnections at the meeting outer ends of the tubular bars forming withthe tubular bars a continuous passageway, pulleys in said hollow pivotalconnections disposed with their axes of rotation transversely of thehollow pivotal connections, a trip cable trained through said tubularbars and over said pulleys, means anchoring the cable at one end to theinitial tubular bar of the lazy tong, a switch Contact connected to theopposite end of the cable in the nal tubular bar of the lazy tong, and aspring asembled with the contact for tensioning the cable and for movingthe contact to circuit closing position when the cable is ruptured.

3. A burglar alarm comprising a lazy tong closure, said lazy tongincluding crossed bars pivotally connected at their crossing andpivotally connected at their ends, certain of the bars being tubular andthe other bars being ilat, said tubular bars being arranged in front ofthe ilat bars to dispose the tubular bars in one row and the ilat barsin a parallel row therewith, links pivotally connecting the outer endsof adjacent tubular bars together, rollers carried by said links, a tripcable trained over said rollers between said links and extendinguninterrupted through said tubular bars, means anchoring the cable atone end to one of the tubular bars, a circuit closer connected to theopposite end of the cable, and a spring connected to the cable fortensioning the cable and for moving the circuit closer to circuitclosing position when the cable is ruptured.

HARRY JACKSON.

